GM Service Manual Online
For 1990-2009 cars only
Figure 1:

OnStar Subsystem


Object Number: 772332  Size: LF
(1)Roof Harness
(2)OnStar Button Assembly
(3)Inside Rearview Mirror
(4)Cellular Antenna
(5)C393
(6)Navigation Antenna
(7)Vehicle Communication Interface Module (VCIM)
(8)C395
(9)C392
Figure 2:

Above Left Side of Package Shelf


Object Number: 695155  Size: MF
(1)C395
(2)C393
(3)Cellular Antenna Coax Connector
(4)C392
(5)Main Body Wiring Harness
Figure 3:

Rear of Left Rear Wheelhouse


Object Number: 924921  Size: LF
(1)Vehicle Communication Interface Module (VCIM)
(2)Wheelhouse-LR